Denmark is shaping up to be wind power's sweetheart. In 2015, it generated 42 percent of its power with wind turbines. It is the highest portion of any country's energy needs fulfilled by wind. And Denmark is no stranger to this podium. In 2014, it fulfilled 39 percent of its energy needs with wind, according to energinet.dk.

Drilling down further, it's even more remarkable in western Denmark. Most of the countries wind turbines are there, and energinet.dk reports that, if we isolate western Denmark, those turbines supplied 55 percent of the power in 2015.

It's also worth noting that Denmark and its surrounding countries have an "energy-exchange" deal. For example, if neighboring country Norway finds itself at a shortfall for energy, Denmark will supply any excess it may have. In western Denmark, where the majority of its wind farms are, those turbines caught more power than western Denmark needed in 1,460 hours of the year's total 8,760 hours. Denmark is generating surplus wind power almost 17 percent of the time.

This highlights the unique arrangement that these countries have in place. Norway is noted for its hydroelectric power, so when Denmark finds itself at a shortfall, it can supplement its power needs from Norway's hydroelectric supplies.

Of course, traditional power generation still plays a major role in Denmark's power supply. Due to the nature of intermittency with alternative energies, traditional power generating plants are a necessity, especially for a country that goes all in with one form of alternative power.

According to energinet.dk, though, Denmark recorded negative energy prices only 1 percent of the time in 2015.

Denmark's parliament is aiming for 50 percent of its power supply from wind by 2020.